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No Model.)

' O. B. PIOKETT.

DRILL TOOTH SPRING.

No. 536,231. Patented Mar-.26, 1895.

Inventor W. S as Attorney same, and Fig. 3, a

' UNITED STATES LATE T OFFICE,

OLIVER B. PIOKETT, OF LIBERTY, INDIANA, AssIGNon TO THE COLUMBIA DRILL COMPANY, OF SAME PLACE.

DRlLL-TO O TH SPRINGJ FEGIFIGATION forming part of Letters Patent No. 536,231, dated March 26, 1 895. Application filed November 5,1894. Serial No. 527.904. tNo model.)

To aZZ whom it may concern.-

Be it known that I, OLIVER B. PICKETT, of Liberty, Union county, Indiana, have invented certain new and useful Improvements in Drill-Tooth Springs, of which the following is a specification. i

This invention pertains to improvements in the depressing springs for the teeth of grain drills and theimprovements will be readily understood from the following description taken in connection with the accompanying drawings, in which-'- Figure 1, is a side elevation of the tooth or hoe of a grain drill provided with my improved spring device; Fig. 2, a plan of the perspective view of the spring device.

In the d'rawingsz-l, indicates theusual drag-bar of a grain drill; 2, the drill tooth or hoe; 3, the usual rock-shaft by means of which the teeth are to be raised or lowered or the spring pressure upon them adjusted, this shaft pin engaging slots 5 and 7 whereby the dragbar is suspended fromthe arm when the pin is in the upper extremityof slot 7 and the lower extremity of slot 5; 9, a'pi'n or equivalent attaching device in the lower portion of link 6 to receive one end of the spring; and 10, a double armed spring having its lower arm connected with the link at 9 and'having its upper arm connected with pin 8.

be no longer suspended but willact upon the ground with a force due to its own weight. If the rocker-arm be moved down still farther till the upper end ofits slot 5 engages pin 8 and moves that 'pin downward somewhat thenthe spring will have been depressed and itspower will be added to the weight of the-tooth. While the machine isworking under such conditions the tooth is held to its work by its weight plus the strain which has been given to the spring and the tooth is at liberty to rise and fall within the limit of the length of slot 5. If the rocker-arm be still farther depressed then the pressure of the spring will be increased.

I claim as my invention- The combination, substantially as set forth, of a drill tooth, a vertically slotted'adjusting device, as a rocker-arm, a pin free to play vertically in such slot, a slotted link engaging such pinand connected with the drill tooth, and aspring connected with said link and pin and tending to urge the pin away from the drill tooth.

OLIVER B. PIOKETT.

Witnesses:

ROBERT E. BORNHART, FRANK B. HUSTED. 

